I have had really bad thunderstorms where everyone in the household freaks out.
I had one in City Living, where a really bad thunderstorm hit, and everyone freaked out. They had a cat, and the poor thing was terrified as well. The family eventually for over it, and comforted the cat, but the bad storm was a negative moodlet for awhile.
As for the other family, the bad thunderstorm hit when they were outside, about to be moved in. Their cat didn't like the noise, but wasn't as freaked out as the cat in the other family. The wife and son got over it, but didn't like the sound, but the dad freaked out for the longest time. I just had him spend some quality time with his wife to distract him, which seemed to work.